JPH06273641A - Optical connector and optical coupler used therefor - Google Patents

Abstract

PURPOSE: To provide an optical coupler of a simple structure with high assembly accuracy and an optical connector for efficiently connecting an arbitrarily arranged optoelectric device(OED) and an optical fiber transmission line by using it. CONSTITUTION: This optical connector 10 is a device for optically connecting a light emission/reception device (OED) 30 connected to a substrate 15 along with a related circuit element and the optical fiber transmission line. Preferably, the OED 30 is surface-mounted to the surface 17 of the substrate 15 and the transmission axis X of the optical fiber transmission line is in almost parallel relation with the surface 17 of the substrate 15. In order to connect the light emission/reception surface 35 of the OED 30 and the transmission axis X of the optical fiber transmission line in optical operation relation, preferably, the optical coupler or an optical axis change means 150 formed by integral molding is arranged between them. Thus, the OED 30 and the optical fiber transmission line are highly accurately connected with the high degree of freedom.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical connector, and more particularly to an optical connector for optically coupling an optical fiber cable and a photoelectric element and an optical coupling device used therefor.

[0002]

Fiber optic transmission lines or fiber optic cables are increasingly used for telecommunications and data transmission, which are generally analog and digital signals, respectively. The advantages of such fiber optic transmission lines over conventional electrical cables are many. For example, fiber optic materials are less expensive than electrical cables. Moreover, the power required to drive the optical signal is less than that required by many electrical cables. Further, the optical transmission of data can increase the information transmission speed over a long distance.

In typical applications, fiber optic connectors require a coupling device that optically couples a fiber optic transmission line with an optoelectronic device (OED). The OED is also electrically coupled to the electronic circuitry that operates with it by two or more wires. In many important applications, electronic circuits, including integrated circuits (ICs), are mounted on printed circuit boards or ceramic substrates. Furthermore, electronic devices such as computers, diagnostic devices, and analytical instruments are often 2
One or more printed circuit boards can be stacked in high density in parallel, satisfying the demand for unlimited miniaturization of electronic devices. In order to enable the use of an optical transmission device in which circuit boards are arranged in high density in parallel, it is usually necessary to put an optical fiber cable in a printed board in a state substantially parallel to the printed board.

In order to maintain parallelism between the fiber optic cable and the associated printed circuit board, conventional connectors have an OED mounted within a cylindrical housing configured to mate coaxially with the ferrule of the fiber optic cable. It has adopted the package structure that has. Such a tubular housing is typically mounted on a case, which in turn is mounted on a printed circuit board containing the associated electronic circuitry.

Conventional optical fiber connectors are disclosed in US Pat. Nos. 4,186,995, 4,222,629, 4,273,413, 4,307,934 and 4,4. No. 911,519.

A typical conventional example of optically coupling an OED to an optical fiber transmission line is shown in FIG. Here, the terms "optical fiber transmission line" or "optical fiber" should be understood as a generic term for single or multicore optical guides. The optical fiber is constructed, for example, by coating glass or a suitable plastic cladding with a material having a refractive index lower than that of the optical fiber itself. It is well known that, as a result, light is totally reflected or refracted by the change in the refractive index of the fiber core, and light is not substantially lost.

According to such a conventional arrangement, a tubular sleeve 200, sometimes referred to as an "active device mount" or "ADM", has an end 201 and is coaxially (or concentrically) attached thereto. An optical ferrule 202 having an optical fiber transmission line 203 is inserted. The end 201 is precision machined and holds the ferrule end 217 to position the fiber end 205.

The ADM 200 also has a flange end 206. This is shown by hatching in the figure. The flange end 206 is configured to permanently attach an assembly, sometimes referred to as a "TO assembly" having a cap 207 and a header assembly 208. Header assembly 2
08 is a hybrid microelectronics (I
C) It may be an assembly, and one or more I
It includes C and passive components 209. This IC may be a pre- or post (pre-stage or post-stage) amplifier, which amplifies or quantizes a signal current input from a photoelectric element such as a photodiode. Further, this IC may be a drive circuit and modulates or controls a light emitting diode or the like. The passive components may be electrical components such as resistors and capacitors. The header assembly is an insulating plate 211 such as a ceramic submount.
, And mount the IC and OED on it. This insulating plate 211 is connected to the metal header 2 through which the lead 213 passes next.
Attach to 12. Some of the leads 213 are insulated by an insulating sleeve 215 extending through the opening of the base plate (metal header) 212. 3 leads or pins 21
Although not all three, at least one is used for input / output signals, one for power, and one for ground.

[0009]

The prior art coupling device shown in FIG. 1 has several drawbacks. For example, such conventional coupling devices require many parts to be assembled and must be precisely aligned with each other. That is, the OED 210 needs to be precisely attached and fixed to the center of the header assembly within a predetermined tolerance. Further, the header assembly 208 is a subassembly (subassembly).
It is necessary to attach and fix to the cap so that
In this case as well, precise alignment is required at the center with a predetermined error. This subassembly must be formed by aligning the lens portion 214 of the cap 207 with the OED 210 again with high precision. This subassembly is AMD20
The OED 210 must be aligned with the center of the hole inside, with a fixed precision of 0. Therefore,
The tolerances associated with the assembly of such conventional packages are cumulative and can result in significant alignment errors. Such errors lead to a considerable loss of signal as the light is transmitted through this coupling device. The accumulated error can result in unrecoverable alignment loss on the order of about 5 dB.

The problem of such "accumulation of manufacturing errors" can be overcome, at least in part, by using the "active alignment" technique of attaching the subassembly to the AMD 200. In this active alignment technique, the OED 210 is temporarily driven, the fiber optic ferrule 202 is placed at the end 201 of the AMD 200, and the mounting position of the subassembly is adjusted to that position and transmitted to or received from the cable 203. It is determined by monitoring the optical signal to be used. While active alignment can improve the light efficiency of such coupling devices,
It has the drawback of further complicating the manufacturing process and increasing the cost of the coupling device.

Furthermore, although the conventional optical connector disclosed in the above-mentioned patent has some excellent features, it also has a drawback that impairs the effectiveness of such a device. For example,
It has a relatively large parasitic impedance, capacitance and resistance due to the many soldered or wire bonded connections between the OED and the substrate. Furthermore, the assembly of such a coupling device and other electronic components is relatively complicated and expensive to manufacture.

Therefore, it is an object of the present invention to provide an optical connector which has a simple manufacturing process and can be manufactured at low cost, and has various improved characteristics.

[0013]

In order to solve the above-mentioned problems, an optical connector according to the present invention comprises a photoelectric element connected to a substrate together with related circuit elements, and at least a part of the substrate to which the photoelectric element is connected. An enclosing case, an optical fiber transmission line attached to the side wall of the case and guided into the case through the side wall, and a transmission axis of the optical fiber transmission line is coupled to a light emitting / receiving surface of the photoelectric element. And an optical coupling device.

An optical connector according to another aspect of the present invention is a photoelectric element which is connected to a surface of a substrate together with related circuit elements and has a light emitting / receiving surface substantially parallel to the surface of the substrate, and the light emitting / receiving element of the photoelectric element. An optical fiber transmission line having a transmission axis arranged substantially parallel to a light receiving surface, and an optical coupling device for optically coupling the transmission axis of the optical fiber transmission line to the light emitting / light receiving surface of the photoelectric element. Get

An optical connector according to still another aspect of the present invention comprises a photoelectric element connected to a surface of a substrate together with related circuit elements, a case surrounding the substrate to which the photoelectric element is connected, and a side wall of the case. Fixing means for fixing one end of the optical fiber transmission line through the formed opening; and an optical coupling device for optically coupling the transmission axis of the optical fiber transmission line to the light emitting / receiving surface of the photoelectric element, The optical coupling device and the fixing means are integrally formed and fixed to the case.

An optical coupling device according to another aspect of the present invention is an optical fiber insertion end into which an optical fiber is inserted from one end of an optical fiber transmission line, and a transmission from the optical fiber transmission line separated from the optical fiber insertion end. And an optical axis changing portion including a reflecting surface that changes the optical path in a direction different from the axis, and has an integral structure for connecting the transmission axis of the optical fiber transmission line to the light emitting / receiving surface of the photoelectric element.

[0017]

The present invention is an improved optical connector for optically coupling between an optical fiber transmission line and an OED electrically interfaced to a substrate. This optical connector is an OED mounted on a substrate such as a printed circuit board.
And a means for attaching the optical fiber transmission line to the substrate, wherein the operating axis or optical axis of the OED does not coincide with the optical transmission axis of the optical fiber transmission line. The optical connector further includes an optical axis changing means for directing the optical axis of the OED along the optical transmission axis of the optical fiber transmission line so that at least a part of the light emitted from the OED is input to the optical fiber transmission line. At least a part of the light emitted from the optical fiber transmission line is incident along the optical axis of the OED. It has been found that the optical connector of the present invention overcomes many of the drawbacks associated with conventional optical connectors of this type.

The present invention also provides a coupling device suitable for this optical connector. In the preferred embodiment, the coupling device includes a light sleeve having a first end, a second end, and a hole between the ends forming an optical passage. The hole cooperates with the optical fiber transmission line so that the optical axis of the optical fiber transmission line is substantially aligned with the optical axis of the hole at the opening at the first end. The optical axis changing means (or the optical bending means) is arranged in an optically cooperative relationship with the optical sleeve. The optical axis changing means, which is preferably arranged at or near the opening at the second end of the hole, cooperates with the optical path of the hole to at least part of the light emitted from the optical fiber transmission line connected to the sleeve OED. To move along the motion (optical) axis. Further, the optical axis changing means may cause at least a part of the light emitted from the OED to travel along the optical fiber transmission line.

The optical connector and the optical coupling device of the present invention may use any of various well-known optical connector types. For example, the present invention may be any of SC type, ST type and FDDI type connectors. SC type optical connector is Japanese N
ANSI X3T9.5, FD proposed by TT
It is a well-known optical connector adopted in the DI and LCF-PMD standards. The ST connector is a well-known optical connector of AT & T, USA. Also, the FDDI connector is manufactured by American AMP Company and is ISO-ICE-9314-3FDDI.
-It is a well-known optical connector standardized to PMD.

The apparatus for coupling an optical fiber transmission line with an OED mounted on a substrate includes means for mounting the optical fiber transmission line on the substrate,
The optical axis of the ED does not match the optical transmission axis of the optical fiber transmission line. The coupling device further includes an optical axis changing means for cooperating with the OED so that at least a part of the light emitted from the OED travels along the optical transmission axis of the optical fiber transmission line or is emitted from the optical fiber transmission line. At least a portion of the emitted light travels along the operating axis of the OED.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the optical connector and its optical coupling device of the present invention will be described in detail below with reference to the accompanying drawings. First, a description will be given with reference to FIG. FIG. 2 is an explanatory diagram of the optical connector 10 according to the embodiment of the present invention. The hybrid circuit element 10 comprises a substrate 15 having connection pins 20 configured to mate with another substrate (not shown). Here, the term "substrate" generally means an electronic circuit element that mounts a circuit element that constitutes an electric circuit. In a typical embodiment,
The substrate 15 is a printed circuit board (PCB), printed wiring board (PWB) and / or similar substrate known to those skilled in the art. In the preferred embodiment, hybrid circuit element 10 is a dual in-line package (D
IP) and is configured to be mountable on a motherboard or another system board of an electronic device. The substrate 15 includes various circuit elements 16 mounted on its surface 17. This printed circuit board may include, for example, a plurality of IC chips. Such chips may be, for example, pre or post amplifiers and additional electronics. Form and nature of such circuit element and substrate 1
Techniques and methods for mounting such elements to 5 are well known to those skilled in the art and therefore do not form part of the present invention.

The OED 30 is the surface 1 of the substrate 15.
7 mounted, and particularly preferably surface mounted (SMT). As used herein, the term "photoelectric device (OED)" means a device that converts current into light and / or light into current. The term "light" generally means electromagnetic radiation, preferably electromagnetic waves of a wavelength to which a semiconductor device sensitively responds whether visible or invisible to the naked human eye.
OEDs such as lasers (eg double channel planar buried heterostructure (DC-PBH), buried crescent (BC), distributed feedback (DFB), distributed Bragg reflector (OBR) etc.), light emitting diodes (LED) (eg surface Emitting LED (SLED), edge emitting LED (ELE
D), super luminescent diode (SLD)
Etc.) or a photodiode (PIN semiconductor, avalanche photodiode (APD), etc.).

The OMT 30 is mounted on the substrate 15 by SMT.
By doing so, the necessary electrical connection between the OED 30 and the substrate 15 can be made through a contact pad or the like on the surface 17 of the substrate 15 as is well known. As is well known to those skilled in the art, such SMT means allows the conventional OED 210 and IC 209 of FIG.
It can be significantly reduced as compared with the parasitic inductance and capacitance caused by the electrical connection between 13 and the printed circuit board. Further, mounting the OED 30 on the substrate 15 can minimize the distance between the device and associated circuit elements. This can further reduce the parasitic inductance and capacitance associated with the optical connector of the present invention. According to the invention, the OED
30 and one or more additional circuit elements 1 on the substrate 15
A wire bond 31 can be used for connection with 6.

The operating axis Z of the OED 30 is the substrate 1
5 can be selected at an arbitrary angle. However, it is preferable that the operating axis of the OED 30 is orthogonal (normal) to the surface 17 of the substrate 15 for the sake of compatibility and easiness with the conventional assembling method. As one of ordinary skill in the art will appreciate, OED 30 generally includes an "active area" or "active surface" that emits light or responds to incident light. Here, the "axis of motion" of these devices means the axis normal to such active area or surface and passing through this center. As shown in FIG. 2, for example, the active area of OED 30 is substantially parallel to surface 17 of substrate 15 and is substantially planar.
It consists of 5. Therefore, the operating axis Z of the OED 30 is substantially normal to the surface 17 of the substrate 15. Therefore, the operating axis Z of the OED, which is an LED, for example, coincides with the average direction of the emitted light from the OED, as shown in FIGS.

The optical connector 10 of the present invention also includes an optical sleeve designated by the reference numeral 40 in FIG. The optical sleeve 40 is optically coupled to an optical fiber transmission line, particularly an optical fiber transmission line 203 contained within a ferrule 202 of the type shown in FIG.

In the preferred embodiment, the optical sleeve 40 is attached to the case 50, and in certain embodiments is preferably integrally formed with the case 50. The case 50 is attached to the substrate 15, and preferably the substrate 1
Environmental protection is provided on the surface 17 of No. 5. The light sleeve 40 preferably extends from the end wall 51 of the case 50 and forms a hole or cavity 45. As will be appreciated by those skilled in the art, the precise shape and size of the optical sleeve 40 and hole 45 will vary greatly depending on the particular size and shape of the fiber optic ferrule to which it is coupled. The optical sleeve 40 preferably has a substantially cylindrical hole. The shape of the hole 45 of the optical sleeve 40 is operatively associated with the optical fiber transmission line so that its optical transmission axis substantially coincides with the X axis of the hole 45. For optical fiber transmission lines that emit light, the term "optical transmission axis" means the average direction of light emitted from the optical fiber cable. In the case of an optical fiber transmission line that receives light, the term "optical transmission axis" means the axis of this transmission line or the average axis of the light receiving end of the optical fiber cable. In FIG. 2, this axis is indicated by the one-dot chain line X. In the preferred embodiment shown in FIG. 2, the light transmission shaft and the hole 4
The axis 5 is substantially parallel to the surface 17 of the substrate 15 and is substantially normal to the optical axis Z of the active region of the OED 30. Further, it is preferable that the operating axis Z of the OED 30 substantially intersects with the optical transmission axis X. Particularly, the ferrule 2 of the type shown in FIG.
It is preferable to intersect the optical fiber transmission line 203 housed in 02. In a more preferred embodiment, these intersection angles are approximately nine.
It is preferably 0 °.

In the optical connector 10 of the present invention, the optical axis changing means (or the optical coupling device) 150 is provided in the operative relationship with the OED 30 and the optical sleeve 40 to change the traveling direction of light. Here, the term “optical operation relation” means that the optical axis changing means is arranged in at least a part of the optical path from the light emitting device, or is arranged in at least a part of the optical path of the light receiving device. It means that the traveling direction of light is changed. Those skilled in the art will appreciate that the optical connector 10 of the present invention is suitable for use in embodiments where the OED 30 comprises a light emitting device or a light receiving device. Further, naturally, the optical fiber transmission line also serves as a light receiving device or a light emitting device, respectively.

In the optical sleeve of the present invention, the optical fiber transmission line produces a light emitting or receiving optical path. Therefore, the optical fiber transmission line is mounted in the optical sleeve due to the optical operation relationship between the optical sleeve and the optical axis changing means. In some cases, ensure that light travels along the proper optical path. According to a preferred embodiment, the optical axis changing means comprises means for changing the direction of a substantial portion of the emitted light from the light emitting device so that a considerable portion of the emitted light is received by the light receiving device. In the case of an embodiment in which the optical fiber transmission line is composed of a graded index fiber having a 62 micron (μ) core and an OED composed of an SLED, the optical coupling efficiency is expected to be about 5 to 10%. ing. On the other hand, in the case of an embodiment in which the optical fiber transmission line is composed of a graded-index fiber having a 62-micron core and an OED made of PIN, the optical coupling efficiency is expected to be about 75 to 98%. .

As will be appreciated by those skilled in the art, the optical connector and the optical coupling device according to the present invention provide advantages and features that could never be achieved or realized by conventional devices. For example, when the OED is a detector (detector), the image of the fiber on the surface of the OED is a receiver (receiver).
Is generally smaller than the active area of. In such an embodiment, the coupling efficiency of the optical connector and the optical coupling device of the present invention is at least 75%, preferably as high as about 85 to 98%. The actual efficiency depends on the design using the invention.
Here, the term "coupling efficiency" means the combined light amount expressed as a percentage of the total available light amount.
Further, the present invention provides an OED optocoupler having an active area that is significantly larger than previously obtained. The reason why such an advantage is obtained is firstly due to the SMT structure of the present invention. This is to reduce the parasitic capacitance. The advantage of the large active area is that the OED on the printed circuit board
The placement dimensional accuracy or the degree of freedom is increased, and the above-described active alignment is unnecessary in a specific embodiment.

According to the present invention, the OED is an SLED.
It has the feature that In the case of such a device, the coupling efficiency of the optical connector and the optical coupling device is about 5 to 1.
It is 0%. However, as will be apparent to one of ordinary skill in the art, the portion of greater light emission can be focused on the image receiving surface of the optical fiber transmission line. For example, an aspherical surface can be used to focus about 40 to 80% of the light emission amount of the OED on such an image receiving surface.
When a high proportion of focused rays is obtained on the image receiving surface,
There are at least two advantages. First, good optical coupling is obtained even if there is a mismatch between the ferrule and the hole. Second
In addition, this feature or advantage minimizes the adverse effects of LED placement errors on the printed circuit board. As mentioned above, active alignment can be eliminated.

The specific structure of the optical axis changing means of the present invention can vary greatly depending on the specific light emitting and receiving device to which the light whose direction is changed is coupled and the relative position of the OED and the optical sleeve. However, in general, the optical axis changing means has a reflection means in optical relationship with the OED and the optical sleeve, and reflects at least a part of the emitted light from the light emitting device to the light receiving device. As will be apparent to those skilled in the art, various configurations are possible for performing this action. For example, one or more mirrors arranged at a predetermined angle with respect to the operating axis of the OED and the optical transmission axis may be used to perform this action. As will be described in more detail below, in the preferred embodiment, such reflecting means is OE.
D and a reflecting surface such as a prism having an inner surface arranged at a predetermined angle with respect to the axis of the optical fiber transmission line.

In order to minimize the signal loss of the optical coupling device of the present invention, this reflecting means is preferably a total reflection prism. In embodiments where the OED comprises a light emitting device, the light emitted from this device may be coherent or non-coherent. For example, the light emitted from the active region of the OED may be in the form of a beam that is substantially parallel to and about the operating axis of the device. In such an embodiment, the optical axis changing means preferably comprises light reflecting means arranged in the beam path. OED
FIG. 3 shows the light trace when using the reflection means associated with the operation of the optical fiber line. A light ray 300 emitted from the OED 30 is substantially parallel to the operating axis Z of the OED 30 and is incident on the reflecting surface 310. This reflecting surface 310 is preferably arranged at an angle of 45 ° with respect to both the operating axis Z and the optical transmission axis X of the optical fiber cable 203, so that the light ray 30
The traveling direction of 0 is changed to be substantially parallel to the optical transmission axis X. Since the light beam has reversibility, the same optical axis changing means 15
0 can be used as well in embodiments where the optical fiber transmission line is a light emitting device.

As will be apparent to those skilled in the art, the optical axis changing means 1
The particular configuration of 50 can be readily modified based on the techniques disclosed herein to optimally accommodate different types of light emitting and receiving devices. For example, O
The light-emitting device of the ED 30 may be a light-emitting device that emits substantially non-coherent light. In that case, the optical axis changing means 150 includes a collimation element such as the lens 330 that is in optical relationship with the OED 30. preferable. An example of this is shown in the light trace diagram in FIG. The primary purpose of the collimation element of the present invention is to collect diffused light from the OED 30 or fiber optic cable end. As is apparent from FIG. 4, the collimated light rays are shown as parallel light rays in the illustrated example, but in reality, they need not be perfectly parallel light rays. The collimation element 330 preferably comprises an optical power surface such as a positive aspherical lens. Such a collimation element is a lens 330.
Is preferably operatively associated with OED 30 by aligning its optical axis with the operating axis Z of OED 30. Thereby, the radiation ray 3 from such non-coherent OED 30
A considerably large part (most) of 00 enters the corner of the lens 330. For aligning the collimated light beam with the light transmission axis X, the optical axis changing means shown in FIG. 4 also preferably includes a reflecting surface 310, which is about 45 ° to each axis.
Place it at the angle. As a result, the traveling direction of the light beam is changed so as to be substantially along the optical transmission axis X of the optical fiber 203.

In the preferred embodiment shown in FIG. 5, the optical axis changing means 150 further has a second lens 340, and the reflecting surface 3
Focus the rays reflected at 10. Lens 340 comprises a powered optical surface such as an aspherical lens. Lens 34
Zero preferably causes the reflected light from reflective surface 310 to coincide with a selected region of the light receiving end of fiber optic transmission line 203.

Optical axis changing means 150 shown in FIGS. 2 to 5.
Has been described as an example in which the OED 30 is a light emitting device and the optical fiber cable 203 is a light receiving device.
However, since the configuration for changing the traveling direction of light is generally reversible, the same configuration as that of FIGS.
It is also applicable when 0 is a light receiving device and the optical fiber cable 203 is a light emitting device. Therefore,
It has been found that the present invention can effectively couple not only the OED which is the photoelectric detector but also the OED which is the light emitting device. As shown in FIG. 5, a suitable optical axis changing means 150 has a first lens 340, a reflecting surface 310 and a second lens 330. Details of this type of embodiment will be described later.

The embodiment shown in FIGS. 2 to 5 is a case where the axis of the optical fiber transmission line intersects with the operating axis of the OED 30 at an angle of 90 °. Although such a configuration is preferable in terms of simplicity, ease of manufacture, and efficiency, it is understood that the relationship between the transmission axis of the optical fiber transmission line and the operating axis of the OED is within the technical scope of the present invention even if it is other than the above. Should be.

Next, description will be made with reference to FIG. A first connector assembly 10 having a DIP structure is disclosed. The DIP connector assembly 10 comprises a conventional 16-pin DIP. O
It has been found that mounting the ED 30 and its associated electronics on the printed circuit board 17 in the DIP significantly reduces the parasitic inductance and capacitance of the fiber optic coupler compared to conventional couplers. The main reason for this is that in conventional coupling devices at least two soldered and / or wirebonded leads extend from the OED (and / or its mounting substrate) to the printed circuit board in the DIP.

The connector assembly 10 comprises a substrate 15, a case 50 and an optical coupling device 60. The substrate 15 includes electronic circuit components 16 disposed on its surface 17. A pin 20 extends downward from the bottom surface of the substrate 15 and is configured to interface with another substrate, for example, a motherboard of an electronic device or a system board. An OED 30 is mounted on the upper surface 17 of the substrate 15.
The OED 30 is SMT-mounted on the printed board by a well-known technique, and further wire-bonded to the circuit element of the printed board by the wire bond 31. To aid in heat dissipation, such an OED 30 may be coupled to a heat sink, such as a large copper ground plane in the printed circuit board, via a copper bias, for example.

The box-shaped case 50 is constructed so as to substantially cover the upper surface 17 of the printed circuit board 15. This case 5
0 is preferably two substantially parallel side walls 53, 54
And two substantially parallel end walls 51, 52, which are connected to each other. End walls 511, 52 and side walls 53, 5
An upper wall 55 that connects the four is provided. A mating sleeve 70, which is preferably configured to mate with the fitting of the fiber optic connector, is coupled to the end wall 51. Such fittings and associated ferrules are well known to those of ordinary skill in the art and will not be described in detail here. The fitting sleeve 70 has a substantially cylindrical hole or cavity 75.
And has a first end 76 of the sleeve for removably receiving an optical fiber transmission line. The hole 75 also forms an opening 77 in the side wall 51 and is configured to permanently receive the optical sleeve portion 61 of the optical coupling device 60.

FIGS. 7 to 10 show another embodiment of the optical connector according to the present invention, which is different from the embodiment shown in FIG. 7 and 8 show an example of a simplex type connector, and FIGS. 9 and 10 show an example of a duplex type connector.

Both of the embodiments of the optical connectors are SC type connectors, which are the type of optical connector disclosed in US Pat. No. 5,042,891. For details, refer to this US Patent Publication.

Referring to FIGS. 7 and 8 showing an embodiment of a simplex type optical connector, the first connector half 71 has a base 73, and at least two elastic catch pieces (engaging pieces) 72 are provided on the base 73. Extends outward from. The elastic catch piece 72 is in the shape of a cantilever, extends parallel to the opposite side of the long axis of the optical sleeve portion 61, and terminates in a protrusion 74 and a lip 76. A rectangular shroud 78 having a slot 79 surrounds the catch piece 72 and provides a base 7
Connect with 3.

The second connector half 80 has a rear portion 82 and a front portion 8.
4 and has an opening 86 on its surface, and is fitted with the first connector half 71. The front part 84 is the first connector half 7
1 and also between the cantilevered catch pieces 72. The opening 86 of a predetermined shape has a notch to locate the protrusion 74 of the first connector half 71 and to extend the longitudinal ridge 89.
Engage slot 79. It will be appreciated that the configuration and operation of the duplex connector shown in FIGS. 9 and 10 is a combination of the two embodiments of FIGS. 7 and 8.

Referring additionally to FIG. 11, the optical coupling device 60 includes an optical sleeve portion 6 connected to an optical axis changing means 150.
1 is included. The optical sleeve portion 61 is the optical fiber transmission line 20.
3 ferrule 202 and is configured to removably mount. In the preferred embodiment shown in these figures, the optical sleeve portion 60 comprises a generally tubular sleeve 40 having a generally tubular bore 45 therein. At the first end of the sleeve 40,
The hole 45 has a generally circular opening 62 through which the ferrule 202 enters the sleeve 40. An optical axis changing means 150 is arranged at the opposite end of the optical sleeve 40 and is in optical communication with the hole 45. Therefore, the hole 45 forms an optical path reaching the second end of the sleeve 40 and the optical axis changing means 150. Further, the hole 45 is configured in operative relationship with the ferrule 202 of the optical fiber 203,
The optical transmission axis of the optical fiber transmission line substantially coincides with the optical axis of the hole 45. That is, the axial holes 45 are precisely molded within the sleeve, all forming a precise longitudinal alignment surface,
It is determined by the size of the optical fiber connector inserted in the shaft hole. In particular, the axial bore 45 includes a shoulder 63 located therein in the exact axial direction. When the fiber optic ferrule is mated with the optical sleeve 40, the ends of ferrule 202 and other portions are maintained in proper contact with shoulder 63. As a result of maintaining this accurate contact, the interval (or distance) between the focusing lens 340 and the end 205 of the optical fiber transmission line 203.
Is fixed exactly. This distance is an important parameter for effective operation of the optical fiber coupling device of the present invention.
This spacing preferably corresponds to the image receiving surface of OED 30.

According to the preferred embodiment of the present invention, the optical coupling device 60 is integrally formed by molding a fluid plastic material so as to eliminate the accumulation of the assembly error of the respective parts. The optical coupling device is preferably formed by molding a moldable plastic material, particularly preferably a high-grade engineering plastic material such as polycarbonate, polyetherimide or polyallylsulfone. Further, the material used to form the case 50 of the present invention, including the mating sleeve portion 70, is preferably substantially opaque to minimize spurious signal generation such as light leakage. Suitable materials for this purpose are plated natural or carbon encapsulated polyallyl sulfones, liquid crystal polymers and zinc. The molding can be performed by a well-known technique such as injection molding, compression molding or transfer molding. The advantage of using a molded coupling device 60 is that the relative size and shape of the optical sleeve 60 and the optical axis changing means 150 are precisely controlled to minimize the accumulation of tolerances.

The optical axis of the lens 340 preferably coincides with the axis of the hole 45. As a result, the optical axis of the lens 340 is substantially aligned with the optical transmission axis of the optical fiber cable mounted on the optical coupling device 60. Furthermore,
The light coupling device 60 is preferably a one-piece or single coupling device, so that error accumulation of alignment between the lens 340 and the axis of the hole 45 can be eliminated or substantially reduced. Therefore, according to the preferred embodiment of the present invention, the optical axis changing means 150 includes an integrally formed lens 340 to close the hole 45. Since the lens 340 is integrally formed at the closed end of the hole 45, the relative axis and the radial position of the lens and the hole, including the shoulder 63 thereof, can be made extremely accurate.

The optical axis changing means 150 shown in FIGS. 6, 11 and 12 comprises a first lens 340, a reflecting surface 310 and a second lens 330. Each of these elements is preferably formed integrally with the optical sleeve 61. The reflecting surface 310 of the optical axis changing means 150 having a surface including the first and second lenses 340 and 330, respectively, is preferably a total reflection prism having a focusing surface.

The optical coupling device 60 is generally a case,
In certain cases, the mating sleeve 70 includes an outer flange 80 for mounting the optical coupling device. As best shown in FIG. 2, a key 81 projects from the bottom of the flange 80 and is configured to fit a slot 90 in the bottom of the sidewall 51. The key 81 of the flange 80 and the slot 90 of the side wall 51 both comprise first means for aligning the optical axis changing means 150 with the OED 30 in an operational relationship. In particular, such a key / slot configuration is the first as will be appreciated by those skilled in the art.
A means for aligning the optical axis Z of the collimation lens 330 is configured so as to have a substantially normal relationship with the printed circuit board 15. Further, the flange 80 preferably includes a first datum surface 82 against which the leading edge of the printed circuit board 15 seats in the assembled coupling device. As shown in FIG. 12, the datum surface 82 is a plane and is substantially parallel to the optical axis of the lens 330, and the OED 30 and the lens 3
Be an accurate reference plane that establishes axial alignment between 30. Since the preferred optical coupling device of the present invention is integrally formed, the exact axial distance between the datum surface 82 and the focusing axis of the lens 330 is accurately established during the optical coupling device formation process. As a result, the optical axis Z of the OED 30 is aligned with the focusing axis of the lens 330 with an extremely small error accumulation.

The optical coupling device 60 further includes a second datum surface 83.
OED3 according to the upper surface 17 of the printed circuit board 15 including
It provides a reference plane that accurately establishes the distance between the active region 35 of 0 and the lens 330.

It will be appreciated that the optical coupling device 60 of the present invention facilitates the assembly of the optical connector of the present invention and minimizes the accumulation of errors that occur during the assembly process. In particular, FIG. 6 and FIG.
2, the assembly of the optical connector preferably first involves fitting the optical sleeve 61 of the optical coupling device 60 with the mating sleeve 7.
It starts by inserting it into the hole 75 of 0. The proper angular orientation of the optical axis changing means 150 of the optical coupling device 60 with the fitting sleeve 70 is ensured by engaging the key 81 with the slot 90. In particular, the engagement of the key 81 and the slot 90 causes the datum surface 83 to be in a direction substantially normal to the side walls 53 and 54, and the upper wall 55.
Guaranteed to be approximately parallel to. Thereby, the datum surface 83 is positioned so as to receive the upper surface 17 of the printed circuit board 15 and to be fitted thereto. Next, the optical coupling device 60 is aligned and connected to the case 50. Optical coupling device 60
Once is connected to the case 50, the printed circuit board 15 is connected to the case 50. Datum surfaces 82 and 83 are OE
D30 is substantially optically aligned with lens 330.
The connection of each element of the optical connector 10 can be realized by using an adhesive such as epoxy or by a well-known technique such as ultrasonic welding. When assembled, the OED 30 serves as the optical axis changing means 150.
The optical relationship with the lens 330 of FIG. Further, when the coupling tool of the optical fiber connector is fitted with the fitting sleeve 70, the ferrule 202 is fitted with the hole 45, and the optical axis changing means 150.
The optical relationship with the lens 340 of FIG.

As shown in FIG. 13, according to an embodiment of the present invention, the optical coupling device 60 further includes additional alignment means so that the optical axis of the lens 330 is laterally aligned with the operating axis Z of the OED 30. To do. In such an embodiment, this lateral alignment comprises one or more alignment pegs 100 extending from the optical coupling device 60. During the assembling process, the peg 100 may be mounted on the socket 110 included in the printed circuit board 15.
Is configured to be mounted exactly. The socket 110 is formed during the manufacture of the printed circuit board 15, and the OED
Precise positioning with respect to the 30 motion axis Z. Further, the position of the peg 100 with respect to the lens 330 can be precisely fixed during formation of the optical coupling device 60. As described above, the optical coupling device 60 of the present invention can be integrally formed by molding a fluid plastic material into a precise dimension. As will be appreciated by those skilled in the art, the tolerance limits between the components of the optical coupler are determined by a single mold operation. Therefore, the use of such a single mold operation can significantly reduce the error accumulation that can occur with conventional devices.

The embodiment of FIG. 13 differs from the embodiments of FIGS. 11 and 12 in that the shoulder 63 formed in the hole 45 is removed and replaced by a spacer element 120 which is a frustoconical cavity 125. different.

FIG. 14 shows still another embodiment of the present invention.
According to this embodiment, the optical coupling device comprises an optical sleeve 40/70 integrally formed with the case 50. In particular, case 50 includes sleeve 40/70 configured to mount ferrule 202. Furthermore, the sleeve 40/70 performs the same function as the mating sleeve 70 of FIGS. That is, it is configured to mate with an optical connector fixture. The optical axis changing means 150 of the optical coupling device includes a first lens 340, an internal reflection surface 310 and a second lens 340.
It is composed of a lens 330. The optical axis changing means of this embodiment is preferably integrally formed of the above-mentioned transparent plastic material. The optical coupler further comprises means for maintaining the optical axis changing means 150 in optical operating relationship with the OED 30 and the optical sleeve 40/70. In particular, this retaining means is
And a housing jacket 170 formed with. The housing jacket 170 is connected to the case 50 through the inner end of the hole 45 of the sleeve 40/70, and has a hole 175.
So that the axis of is substantially coincident with the axis X of the hole 45. A lens 340 is mounted on the first ends of the axial holes 45, 175 and is closed so that the axis of the lens 340 is aligned with the axis X and the axis of the lens 330 is aligned with the operating axis of the OED 30. . The housing jacket 170 has an end wall 178, which partially closes the shaft bore 45.
The end wall 178 includes a generally circular aperture 180, which defines an optical path along the axis X to the lens 340. Although the housing jacket 170 is shown as a separate member in FIG. 14 and is mounted in the hole 45, the hole 45 may be integrally formed and may have a cavity for mounting the lens 340 therein.

The preferred embodiments of the optical connector of the present invention and the optical coupling member used therefor have been described above. But,
It should be understood by those skilled in the art that the present invention should not be limited to such embodiments, and that various modifications and changes can be made according to the application without departing from the gist of the present invention.

[0055]

As can be understood from the above description, the optical connector of the present invention and the optical coupling device used therein have various practically remarkable effects. Even if the optical axes of the light emitting or receiving OED and the optical fiber for optical transmission do not coincide with each other, the optical axis changing means or the optical coupling device can couple the two in an optical operation relationship. Therefore, the OED and related electronic circuit elements can be directly connected to the printed circuit board by SMT technique to minimize parasitic inductance, capacitance and resistance. Further, the degree of freedom in the arrangement between the OED and the optical fiber transmission line is increased, and the assembly workability can be greatly improved. Furthermore, by integrally molding an optical coupling device having an optical axis changing means such as a lens and a reflecting surface with a plastic material and mounting it in a case, not only the workability of assembling the optical connector is improved but also an integrated structure is provided. Therefore, there is no accumulated error and high accuracy can be obtained as compared with the conventional device composed of a large number of parts.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a conventional optical connector.

FIG. 2 is a schematic diagram of an embodiment of the optical connector of the present invention.

FIG. 3 is a configuration diagram of a first embodiment of an optical coupling device of the present invention that couples an orthogonal coherent light source and a light receiving element.

FIG. 4 is a configuration diagram of a second embodiment of an optical coupling device of the present invention that couples an orthogonal non-coherent light source and a light receiving element.

FIG. 5 is a configuration diagram of a third embodiment of an optical coupling device of the present invention that couples an orthogonal non-coherent light source and a light receiving element.

FIG. 6 is a partially cutaway exploded perspective view of the first embodiment of the optical connector of the present invention.

FIG. 7 is a partially cutaway exploded perspective view of a simplex type optical connector according to an embodiment of the present invention.

8 is a perspective view for explaining a fitted state of the simplex optical connector of FIG.

FIG. 9 is a partially cutaway exploded perspective view of a duplex type optical connector according to an embodiment of the present invention.

FIG. 10 is a perspective view illustrating a fitted state of the duplex optical connector of FIG.

FIG. 11 is a vertical cross-sectional view of the first embodiment of the optical coupling device of the present invention.

12 is a sectional view of an embodiment of the optical connector of the present invention using the optical coupling device of FIG.

FIG. 13 is a sectional view of an optical connector of the present invention using a modified embodiment of the optical coupling device.

FIG. 14 is a sectional view of an optical connector of the present invention using still another embodiment of the optical coupling device.

[Explanation of symbols]

 10 Optical Connector 30 Photoelectric Element (OED) 35 Light Emitting / Receiving Surface 15 Substrate 17 Substrate Surface 50 Case 51 Sidewall 150 Optical Coupling Device 203 Optical Fiber Transmission Line 310 Reflecting Surface 330, 340 Lens

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Francis Thomas De La Hantey United States of America Pennsylvania 18940 Newton Carmel Place 6 (72) Inventor Allen Haney United States New Jersey 08904 Highland Park North Fifth Avenue 292 (72) Inventor Bill Henry Reisen United States of America New Jersey 08886 Stuartsville Thomson Street 511 (72) Inventor Richard Gregory Welerer United States New Jersey 08691 Robinsville Galston Drive 4

Claims (4)

[Claims] 1. A photoelectric element connected to a substrate together with related circuit elements, a case that at least partially surrounds the substrate to which the photoelectric element is connected, and a case mounted on a side wall of the case through the side wall. An optical connector comprising: an optical fiber transmission line guided into the case; and an optical coupling device for coupling a transmission axis of the optical fiber transmission line to a light emitting / receiving surface of the photoelectric element. 2. A photoelectric element, which is connected to a surface of a substrate together with related circuit elements, and has a light emitting / light receiving surface substantially parallel to the surface of the substrate; and a photoelectric element arranged substantially parallel to the light emitting / light receiving surface of the photoelectric element. An optical connector comprising: an optical fiber transmission line having a transmission axis; and an optical coupling device for optically coupling the transmission axis of the optical fiber transmission line to the light emitting / receiving surface of the photoelectric element. . 3. A photoelectric element connected to a surface of a substrate together with related circuit elements, a case surrounding the substrate to which the photoelectric element is connected, and an optical fiber transmission through an opening formed in a side wall of the case. Fixing means for fixing one end of the line, and a transmission axis of the optical fiber transmission line for emitting light from the photoelectric element /
An optical connector comprising: an optical coupling device that is optically coupled to a light-receiving surface; and the optical coupling device and the fixing means are integrally formed and fixed to the case. 4. An optical fiber insertion end into which an optical fiber is inserted from one end of an optical fiber transmission line, and a reflecting surface which is separated from the optical fiber insertion end and changes an optical path in a direction different from the transmission axis of the optical fiber transmission line. And an optical axis changing unit including the optical axis changing unit, the optical axis changing unit including the optical axis changing unit including the optical axis changing unit.